The defuse vs. diffuse word choice argument is just another example of how the English language can be very tricky at times.  This quick guide will clear up the difference between the two terms to help you overcome any future mistakes when using them.

Defuse and diffuse sound awfully similar, but, as is almost always the case, they have completely different meanings.  These two terms are nearly homonyms, but they have pronunciations that are a tad different.  Defuse has a strong “e” sound, such as in the term “deep.”  Diffuse, on the other hand, has an “i” that sounds similar to the one used in the term “list.”

As for their definitions, defuse refers to making something, typically a situation, less tense or dangerous.  Defuse can also refer to the act of removing a fuse from a bomb or other explosive device, as in de-fuse.

I had to defuse the situation before a fight broke out.

The expert was called in to defuse the bomb.

Diffuse refers to the act of pouring out and spreading a fluid or to spread something and scatter it widely.  In the realm of physics, diffuse also means to spread by diffusion, which is when particles or objects move away from one another.  Diffused light is one such example.

The bright light diffused across the studio.

Perhaps the best way to remember the difference between the two is to separate “de” and “fuse” when speaking.  You are taking the fuse out of something to lessen its explosive potential, whether it’s a situation or a bomb.